Source: John Sellars, Stoicism (Berkeley: University of California Press, 2006) 53.
"When one of his students interrupts and says that studying logic is a waste of time because it will not help him improve his character, Epictetus replies by saying how can any of us hope to do that unless we are able to define what it is that we hope to improve and are able to distinguish between truth and falsehood."
This quote is from a chapter that discusses the Platonic idea that to know the good is to love and do the good. The Stoics somewhat agreed with Plato on that, yet they maintained that truly "knowing" the good often entailed a lot of time, practice, and discipline. It's not just a matter of hearing information and becoming instantaneously transformed, as far as the Stoics were concerned!
The quote seems to talk about a light going on in a darkened mind. A person realizes that he's supposed to live a certain way, and logic inexorably points him in that direction. He can now work on building character, since he know what good character is, and why it actually is good.
In my I Clement quiet time, I read 17:17 (in the Lost Books of the Bible and the Forgotten Books of Eden), which states that Christ enlightened the darkened mind. I'm not entirely sure what's going on in Clement's head, but it reminds me of what I got from Tim Keller in my time in New York: when we truly receive the Gospel of God's free grace through Christ, our perspective is changed in so many ways. We are touched by God's love, and that influences how we view and treat ourselves, our neighbors, and society.
That's kind of a Platonic way of seeing things: know something to be true and right, and you automatically do it. But is this always the perspective of the Bible? Not necessarily, for James says that faith without works is dead, and that the demons believe God is one and tremble. One apparently can have correct knowledge without it changing his life for the better.
A relevant topic is the villain on the last episode of Joan of Arcadia. On some level, he knows God, since God spoke to him. Still, he hates God. At the same time, what he believes about God is not necessarily so, for he thinks that God forsakes people and is a love-starved, narcissistic deity. If he truly knew God's love, would he believe that way and act accordingly? I'm not sure. It's possible. Lucifer knew God, yet he pursued power rather than receiving God's love.